Transparent polycarbonate polyester composition and process

ABSTRACT

Disclosed is a transparent/translucent molding composition and process for making prepared from an impact modifier and a resin blend of polycarbonate and a cycloaliphatic polyester having a matching index of refraction.

This application is a continuation in part of U.S. patent applicationSer. No. 09/891,731, filed Jun. 26, 2001, now abandoned; Ser. No.09/690,341, filed Oct. 17, 2000, now abandoned; and Ser. No. 09/690,342,filed Oct. 17, 2000, now abandoned, all of the are incorporated hereinby reference.

FIELD OF THE INVENTION

This invention relates to transparent or translucent thermoplasticmolding compositions, optionally containing visual-effect colorants andother additives and processes for producing such compositions.

BACKGROUND OF THE INVENTION

Polycarbonate (PC) is a high-performance plastic with good impactstrength. In addition to ductility (impact strength), general-purpose PChas high transparency, good dimensional stability, low water absorption,good stain resistance and a wide range of colorability. A weak area forPC is its relatively limited range of chemical resistance, whichnecessitates careful appraisal of applications involving contact withcertain organic solvents, some detergents, strong alkali, certain fats,oils and greases. Also, another weak area of PC is that it has a highmelt viscosity which makes it difficult to mold. Medium to high flow PCgrades suffer from the fact that the low temperature ductility issacrificed for a better flow. Finally, PC formulations withvisual-effect additives like metallic type pigments or mineral flakesare in general very brittle at room temperature. This invention dealswith these shortcomings and as such proposes a material that has anunique property profile in terms of transparency, improved chemicalresistance, higher flow and low temperature ductility at −20 to −40° C.,even with special-effect colorants.

A widely used method to increase low temperature impact resistance, isthe addition of impact modifiers to the PC compositions. Adding minoramounts of methylacrylate-butadiene-styrene (MBS) rubbers orAcrylonitrile-butadiene-styrene (ABS) rubbers results in lower D/Btransition temperatures. The major drawback of these modifications isthat, even with only 1% addition levels, the transparency decreases,taking away one of the key properties of PC.

This opaqueness is caused by the relatively high refractive index (RI)of the aromatic PC (1.58) compared to the more aliphatic rubbery and/orsiloxane components, which have RI values in the range 1.48–1.56.

U.S. Pat. No. 6,040,382 describes how optical clarity of a blend of 2transparent, immiscible polymers can be improved by addition of a thirdpolymer which is selectively miscible with one of the two originalimmiscible polymers. The concept is based on matching refractiveindexes. This patent is directed to compositions of monovinylaromatic-conjugated diene copolymers (like styrene-butadiene blockcopolymers), styrene-maleic anhydride copolymers (SMA) and poly(alpha-methylstyrene).

U.S. Pat. No. 5,891,962; U.S. Pat. No. 5,494,969; and U.S. Pat. No.5,614,589; respectively, describe specific formulations of rubbermodified styrene; cycloolefin polymer composites; andmethacrylate-acrylonitrile-butadiene-styrene copolymers with urethanecopolymer. In these compositions, polymers are being replaced byco-polymers (f.i. polystyrene by a co-polymer of styrene andalkyl(meth)acrylate) to match the RI of a rubbery component. It's alsopossible to modify the rubbery component to match the RI of the polymermatrix, like in U.S. Pat. No. 5,321,056 and U.S. Pat. No. 5,409,967assigned to Rohm and Haas. The focus of all these patents is tochemically modify the ingredients to match RI to achieve transparency.Matching RI to achieve transparency is as such not a novelty.

U.S. Pat. No. 5,859,119 to Hoefflin relates to reinforced, moldingcompositions with desirable ductility and melt flow properties. Thecomposition contains a cyclo aliphatic polyester resin, an impactmodifying amorphous resin which increases the ductility of the polyesterresin but reduces the melt flow properties thereof, and a high molecularweight polyetherester polymer which increases the melt flow propertiesof the polyester polymer without reducing the ductility thereof, and aglass filler to reinforce and stiffen the composition and form areinforced molding composition. This invention is focussed on opaque PCblends, rather than transparent blends.

U.S. Pat. No. 4,188,314 describes shaped articles (such as sheet andhelmets) of blends of 25–98 parts by weight (pbw) of an aromaticpolycarbonate and 2–75 pbw of a poly cyclohexane dimethanol phthalatewhere the phthalate is from 5–95% isophthalate and 95–10% terephthalate.Articles with enhanced solvent resistance and comparable opticalproperties and impact to the base polycarbonate resin and superioroptical properties to an article shaped from a polycarbonate and anaromatic polyester, such as polyalkylene terephthalate, are disclosed.

There are other patents that deal with polycarbonate polycyclohexanedimethanol phthalate blends for example; U.S. Pat. No. 4,125,572; U.S.Pat. Nos. 4,391,954; 4,786,692; 4,897,453 and 5,478,896. U.S. Pat. No.5,478,896 relates to transparent polycarbonate blends with 10–99%polyester of CHDM with some minor amount of aliphatic diol and iso andterephthalic acid. U.S. Pat. No. 4,786,692 relates to a 2–98% aromaticpolycarbonate blend with a polyester made of cyclohexane dimethanol(CHDM) and ethylene glycol (EG) in a 1:1 to 4:1 ratio with iso andterephthalic acid. U.S. Pat. No. 4,391,954 describes compatiblecompositions of non halogen polycarbonate (PC) and amorphous polyestersof CHDM and a specific iso/tere phthalate mixture. U.S. Pat. No.4,125,572 relates to a blend of 40–95% PC, 5–60% polybutyleneterephthalate (PBT) 1–60% and 1–60% an aliphatic/cycloaliphaticiso/terephthalate resin. U.S. Pat. No. 4,897,453 describes blends of10–90% PC, 10–90% of a polyester of 0.8–1.5 IV, comprised of1,4-cyclohexane dicarboxylic acid, 70% trans isomer, CHDM and 15–50 wt.% poly oxytetramethylene glycol with 0–1.5 mole % branching agent. Alsoclaimed are molded or extruded articles of the composition.

SUMMARY OF THE INVENTION

The present invention provides compositions with improved ductility andmelt flow propeties, and good baseline transparency, which can then bereduced if and as desired for a specific application by the addition ofvisual-effects additives. The composition comprises a uniform blend of:

-   -   (a) a miscible resin blend of a polycarbonate resin and a        cycloaliphatic polyester resin, said cycloaliphatic polyester        resin comprising the reaction product of an aliphatic C₂–C₁₂        diol or chemical equivalent and a C₆–C₁₂ aliphatic diacid or        chemical equivalent, said cycloaliphatic polyester resin        containing at least about 80% by weight of a cycloaliphatic        dicarboxylic acid, or chemical equivalent, and/or of a        cycloaliphatic diol or chemical equivalent;    -   (b) an impact modifying amorphous resin having a refractive        index from about 1.51 to about 1.58 for increasing the low        temperature ductility of the resin molding composition;        wherein the proportions in the blend of polycarbonate and the        cycloaliphatic polyester resin are selected so that the index of        refraction substantially matches the index of refraction of said        impact modifier.

In one embodiment, transparent and low temperature ductile polycarbonate(PC) blends are obtained via the addition of poly(cyclohexane dimethanolcyclohexane dicarboxylate) (PCCD) and an impact modifier. The completemiscibility of PC and PCCD permits the matching of refractive index (RI)of the impact modifier with the RI of the PC/PCCD blend, by adjustingthe PC/PCCD ratio. Examples of such impact modifiers are MBS/ABS type ofrubbers with a particle size range from 50–1000 nm, the rubber beingbutadiene or styrene-butadiene with styrene content of up to 40%.Styrene to acrylonitrile ratio in ABS rubbers can be between 100/0 and50/50 with a preferred ratio of 80/20 to 70/30. Typical examples are ABS415 (RI=1.542) and ABS 336 (RI=1.546), both produced by GE Plastics andBTA702, BTA736, being MBS materials and produced by Rohm & Haas. Allthese rubbers are used in the PVC market as impact modifiers to improvethe toughness of PVC without loosing the transparency.

The application further provides a method for the production ofcompositions with improved ductility and melt flow propeties, and goodbaseline transparency, which can then be reduced if and as desired for aspecific application by the addition of visual-effects additives. Inaccordance with one embodiment of the method of the invention, amiscible resin blend of a polycarbonate resin and a cycloaliphaticpolyester resin is prepared. The proportions of the polycarbonate resinand the cycloaliphatic polyester resin are selected such that the blendhas a refractive index that is intermediate between the refractiveindices of the two components, and that substantially matches therefractive index of an impact modifier which is added to form the finalcomposition.

DETAILED DESCRIPTION OF THE INVENTION

The composition of the present invention comprise miscible resin blendof a polycarbonate resin and a cycloaliphatic polyester resin, saidcycloaliphatic polyester resin comprising the reaction product of analiphatic C₂–C₁₂ diol or chemical equivalent and a C₆–C₁₂ aliphaticdiacid or chemical equivalent, said cycloaliphatic polyester resincontaining at least about 80% by weight of a cycloaliphatic dicarboxylicacid, or chemical equivalent, and/or of a cycloaliphatic diol orchemical equivalent.

Polycarbonate Resin

Polycarbonates useful in the invention comprise the divalent residue ofdihydric phenols, Ar′, bonded through a carbonate linkage and arepreferably represented by the general formula III:

wherein A is a divalent hydrocarbon radical containing from 1 to about15 carbon atoms or a substituted divalent hydrocarbon radical containingfrom 1 to about 15 carbon atoms; each X is independently selected fromthe group consisting of hydrogen, halogen, and a monovalent hydrocarbonradical such as an alkyl group of from 1 to about 8 carbon atoms, anaryl group of from 6 to about 18 carbon atoms, an arylalkyl group offrom 7 to about 14 carbon atoms, an alkoxy group of from 1 to about 8carbon atoms; and m is 0 or 1 and n is an integer of from 0 to about 5.Ar′ may be a single aromatic ring like hydroquinone or resorcinol, or amultiple aromatic ring like biphenol or bisphenol A.

The dihydric phenols employed are known, and the reactive groups arethought to be the phenolic hydroxyl groups. Typical of some of thedihydric phenols employed are bis-phenols such asbis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane (also knownas bisphenol-A), 2,2-bis(4-hydroxy-3,5-dibromo-phenyl)propane; dihydricphenol ethers such as bis(4-hydroxyphenyl)ether,bis(3,5-dichloro-4-hydroxyphenyl)ether; p,p′-dihydroxydiphenyl and3,3′-dichloro-4,4′-dihydroxydiphenyl; dihydroxyaryl sulfones such asbis(4-hydroxyphenyl)sulfone, bis(3,5-dimethyl-4-hydroxyphenyl)sulfone,dihydroxy benzenes such as resorcinol, hydroquinone, halo- andalkyl-substituted dihydroxybenzenes such as1,4-dihydroxy-2,5-dichlorobenzene, 1,4-dihydroxy-3-methylbenzene; anddihydroxydiphenyl sulfides and sulfoxides such asbis(4-hydroxyphenyl)sulfide, bis(4-hydroxy-phenyl)sulfoxide andbis(3,5-dibromo-4-hydroxyphenyl)sulfoxide. A variety of additionaldihydric phenols are available and are disclosed in U.S. Pat. Nos.2,999,835, 3,028,365 and 3,153,008; all of which are incorporated hereinby reference. It is, of course, possible to employ two or more differentdihydric phenols or a combination of a dihydric phenol with a glycol.

The carbonate precursors are typically a carbonyl halide, adiarylcarbonate, or a bishaloformate. The carbonyl halides include, forexample, carbonyl bromide, carbonyl chloride, and mixtures thereof. Thebishaloformates include the bishaloformates of dihydric phenols such asbischloroformates of 2,2-bis(4-hydroxyphenyl)-propane, hydroquinone, andthe like, or bishaloformates of glycol, and the like. While all of theabove carbonate precursors are useful, carbonyl chloride, also known asphosgene, and diphenyl carbonate are preferred.

The aromatic polycarbonates can be manufactured by any processes such asby reacting a dihydric phenol with a carbonate precursor, such asphosgene, a haloformate or carbonate ester in melt or solution. U.S.Pat. No. 4,123,436 describes reaction with phosgene and U.S. Pat. No.3,153,008 describes a transesterification process.

Preferred polycarbonate will be made of dihydric phenols that result inresins having low birefringence for example dihydric phenols havingpendant aryl or cup shaped aryl groups like:

-   Phenyl-di(4-hydroxyphenyl)ethane (acetophenone bisphenol):-   Diphenyl-di(4-hydroxyphenyl)methane (benzophenone bisphenol):-   2,2-bis(3-phenyl-4-hydroxyphenyl)propane-   2,2-bis-(3,5-diphenyl-4-hydroxyphenyl)propane;-   bis-(2-phenyl-3-methyl-4-hydroxyphenyl)propane;-   2,2′-bis(hydroxyphenyl)fluorene;-   1,1-bis(5-phenyl-4-hydroxyphenyl)cyclohexane;-   3,3′-diphenyl-4,4′-dihydroxy diphenyl ether;-   2,2-bis(4-hydroxyphenyl)-4,4-diphenyl butane;-   1,1-bis(4-hydroxyphenyl)-2-phenyl ethane;-   2,2-bis(3-methyl-4-hydroxyphenyl)-1-phenyl propane;-   6,6′-dihdyroxy-3,3,3′,3′-tetramethyl-1,2′-spiro(bis)indane;

(hereinafter “SBI”), or dihydric phenols derived from spiro biindane offormula IV:

Units derived from SBI and its 5-methyl homologue are preferred, withSBI being most preferred.

Other dihydric phenols which are typically used in the preparation ofthe polycarbonates are disclosed in U.S. Pat. Nos. 2,999,835, 3,038,365,3,334,154 and 4,131,575. Branched polycarbonates are also useful, suchas those described in U.S. Pat. Nos. 3,635,895 and 4,001,184.Polycarbonate blends include blends of linear polycarbonate and branchedpolycarbonate.

It is also possible to employ two or more different dihydric phenols ora copolymer of a dihydric phenol with an aliphatic dicarboxylic acidslike; dimer acids, dodecane dicarboxylic acid, adipic acid, azelaic acidin the event a carbonate copolymer or interpolymer rather than ahomopolymer is desired for use in the preparation of the polycarbonatemixtures of the invention. Most preferred are aliphatic C5 to C12 diacidcopolymers.

The preferred polycarbonates are preferably high molecular weightaromatic carbonate polymers have an intrinsic viscosity (as measured inmethylene chloride at 25° C.) ranging from about 0.30 to about 1.00dl/gm. Polycarbonates may be branched or unbranched and generally willhave a weight average molecular weight of from about 10,000 to about200,000, preferably from about 20,000 to about 100,000 as measured bygel permeation chromatography. It is contemplated that the polycarbonatemay have various known end groups.

Cycloaliphatic Polyester Resin

The cycloaliphatic polyester resin comprises a polyester havingrepeating units of the formula I:

where at least one R or R1 is a cycloalkyl containing radical.

The polyester is a condensation product where R is the residue of anaryl, alkane or cycloalkane containing diol having 6 to 20 carbon atomsor chemical equivalent thereof, and R1 is the decarboxylated residuederived from an aryl, aliphatic or cycloalkane containing diacid of 6 to20 carbon atoms or chemical equivalent thereof with the proviso that atleast one R or R1 is cycloaliphatic. Preferred polyesters of theinvention will have both R and R1 cycloaliphatic.

The present cycloaliphatic polyesters are condensation products ofaliphatic diacids, or chemical equivalents and aliphatic diols, orchemical equivalents. The present cycloaliphatic polyesters may beformed from mixtures of aliphatic diacids and aliphatic diols but mustcontain at least 50 mole % of cyclic diacid and/or cyclic diolcomponents, the remainder, if any, being linear aliphatic diacids and/ordiols. The cyclic components assist by imparting good rigidity to thepolyester and to allow the formation of transparent blends due tofavorable interaction with the polycarbonate resin.

The polyester resins are typically obtained through the condensation orester interchange polymerization of the diol or diol equivalentcomponent with the diacid or diacid chemical equivalent component. Twotypes of cycloaliphatic polyesters can be used with BPA-basedpolycarbonate to give the compositions and articles of this invention.The most preferred polyester molecules are derived from cycloaliphaticdiol and cycloaliphatic diacid compounds, for example polycyclohexanedimethanol cyclohexyl dicarboxylate (PCCD). Polyesters having only onecyclic unit may also be useful. An extra advantage of adding thesealiphatic polyesters to PC is that their low glass transitiontemperature (Tg) improves the flow of PC (or impact modified PC)significantly, resulting in an overall very favorable flow/impactbalance. Another advantage is that the polyester improves the overallchemical resistance towards various chemicals that are very aggressivetowards straight PC. Examples of these chemicals are acetone,coppertone, gasoline, toluene etc.

R and R1 are preferably cycloalkyl radicals independently selected fromthe following formula:

The preferred cycloaliphatic radical R1 is derived from the1,4-cyclohexyl diacids and most preferably greater than 70 mole %thereof in the form of the trans isomer. The preferred cycloaliphaticradical R is derived from the 1,4-cyclohexyl primary diols such as1,4-cyclohexyl dimethanol, most preferably more than 70 mole % thereofin the form of the trans isomer.

Other diols useful in the preparation of the polyester resins of thepresent invention are straight chain, branched, or cycloaliphatic alkanediols and may contain from 2 to 12 carbon atoms. Examples of such diolsinclude but are not limited to ethylene glycol; propylene glycol, i.e.,1,2- and 1,3-propylene glycol; 2,2-dimethyl-1,3-propane diol; 2-ethyl,2-methyl, 1,3-propane diol; 1,3- and 1,5-pentane diol; dipropyleneglycol; 2-methyl-1,5-pentane diol; 1,6-hexane diol; dimethanol decalin,dimethanol bicyclo octane; 1,4-cyclohexane dimethanol and particularlyits cis- and trans-isomers; 2,2,4,4-tetramethyl-1,3-cyclobutanediol(TMCBD), triethylene glycol; 1,10-decane diol; and mixtures of any ofthe foregoing. Preferably a cycloaliphatic diol or chemical equivalentthereof and particularly 1,4-cyclohexane dimethanol or its chemicalequivalents are used as the diol component.

Chemical equivalents to the diols include esters, such as dialkylesters,diaryl esters and the like.

The diacids useful in the preparation of the aliphatic polyester resinsof the present invention preferably are cycloaliphatic diacids. This ismeant to include carboxylic acids having two carboxyl groups each ofwhich is attached to a saturated carbon. Preferred diacids are cyclo orbicyclo aliphatic acids, for example, decahydro naphthalene dicarboxylicacids, norbornene dicarboxylic acids, bicyclo octane dicarboxylic acids,1,4-cyclohexanedicarboxylic acid or chemical equivalents, and mostpreferred is trans-1,4-cyclohexanedicarboxylic acid or chemicalequivalent. Linear dicarboxylic acids like adipic acid, azelaic acid,dicarboxyl dodecanoic acid and succinic acid may also be useful.

Cyclohexane dicarboxylic acids and their chemical equivalents can beprepared, for example, by the hydrogenation of cycloaromatic diacids andcorresponding derivatives such as isophthalic acid, terephthalic acid ornaphthalenic acid in a suitable solvent such as water or acetic acidusing a suitable catalysts such as rhodium supported on a carrier suchas carbon or alumina. See, Friefelder et al., Journal of OrganicChemistry, 31, 3438 (1966); U.S. Pat. Nos. 2,675,390 and 4,754,064. Theymay also be prepared by the use of an inert liquid medium in which aphthalic acid is at least partially soluble under reaction conditionsand with a catalyst of palladium or ruthenium on carbon or silica. See,U.S. Pat. Nos. 2,888,484 and 3,444,237.

Typically, in the hydrogenation, two isomers are obtained in which thecarboxylic acid groups are in cis- or trans-positions. The cis- andtrans-isomers can be separated by crystallization with or without asolvent, for example, n-heptane, or by distillation. The cis-isomertends to blend better; however, the trans-isomer has higher melting andcrystallization temperatures and may be preferred. Mixtures of the cis-and trans-isomers are useful herein as well.

When the mixture of isomers or more than one diacid or diol is used, acopolyester or a mixture of two polyesters may be used as the presentcycloaliphatic polyester resin.

Chemical equivalents of these diacids include esters, alkyl esters,e.g., dialkyl esters, diaryl esters, anhydrides, salts, acid chlorides,acid bromides, and the like. The preferred chemical equivalents comprisethe dialkyl esters of the cycloaliphatic diacids, and the most favoredchemical equivalent comprises the dimethyl ester of the acid,particularly dimethyl-1,4-cyclohexane-dicarboxylate.

A preferred cycloaliphatic polyester is poly(cyclohexane-1,4-dimethylenecyclohexane-1,4-dicarboxylate) also referred to aspoly(1,4-cyclohexane-dimethanol-1,4-dicarboxylate) (PCCD) which hasrecurring units of formula II:

With reference to the previously set forth general formula, for PCCD, Ris derived from 1,4 cyclohexane dimethanol; and R1 is a cyclohexane ringderived from cyclohexanedicarboxylate or a chemical equivalent thereof.The favored PCCD has a cis/trans formula.

The polyester polymerization reaction is generally run in the melt inthe presence of a suitable catalyst such as a tetrakis (2-ethyl hexyl)titanate, in a suitable amount, typically about 50 to 200 ppm oftitanium based upon the final product.

The preferred aliphatic polyesters used in the present transparentmolding compositions have a glass transition temperature (Tg) which isabove 50° C., more preferably above 80° C. and most preferably aboveabout 100° C.

Also contemplated herein are the above polyesters with from about 1 toabout 50 percent by weight, of units derived from polymeric aliphaticacids and/or polymeric aliphatic polyols to form copolyesters. Thealiphatic polyols include glycols, such as poly(ethylene glycol) orpoly(butylene glycol). Such polyesters can be made following theteachings of, for example, U.S. Pat. Nos. 2,465,319 and 3,047,539.

Miscible Resin Blend

In the miscible resin blend of the invention, the preferredpolycarbonate will be composed of units of BPA, SBI bisphenol, arylsubstituted bisphenols, cycloaliphatic bisphenols and mixtures thereof.The most preferred materials will be blends where the polyester has bothcycloaliphatic diacid and cycloaliphatic diol components specificallypolycyclohexane dimethanol cyclohexyl dicarboxylate (PCCD).

In the miscible resin blends, a ratio of cycloaliphatic polyester topolycarbonate in the range of 80:20 to 5:95% by weight of the entiremixture is preferred. Blends from 70:30 to 40:60 are most preferred.

The refractive index of the miscible resin blend is determined by thecomponents and the amounts of each. The refractive index of purepolycarbonate (PC) is 1.586 while that of PCCD is 1.516. In a mixture ofpolycarbonate and poly(1,4-cyclohexanedimethanol-1,4-cyclohexanedicarboxylate the refractiveindex of the mixture, y, varies as the function −0.0007 (weight percentpoly (1,4-cyclohexanedimethanol-1,4-cyclohexanedicarboxylate)+1.586 witha regression R squared coefficient of 0.998. Similarly, resorcinoldiphosphate (RDP) has a refractive index of 1.5673. A mixture having 25weight percent RDP in PC would result in a calculate refractive index of0.25(1.5673)+0.75(1.586)=1.581. Thus the refractive index of the mixtureof the two components may be controlled between the upper and lowerlimits of their respective indices of refraction.

Impact Modifier

The compositions of the invention further comprise a substantiallyamorphous impact modifier copolymer resin that is added to the miscibleresin blend in an amount between about 1 and 30% by weight. The impactmodifier may comprise one of several different rubbery modifiers such asgraft or core shell rubbers or combinations of two or more of thesemodifiers. Suitable are the groups of modifiers known as acrylicrubbers, ASA rubbers, diene rubbers, organosiloxane rubbers, EPDMrubbers, SBS or SEBS rubbers, ABS rubbers, MBS rubbers and glycidylester impact modifiers.

The term acrylic rubber modifier can refer to multi-stage, core-shell,interpolymer modifiers having a cross-linked or partially crosslinked(meth)acrylate rubbery core phase, preferably butyl acrylate. Associatedwith this cross-linked acrylic ester core is an outer shell of anacrylic or styrenic resin, preferably methyl methacrylate or styrene,which interpenetrates the rubbery core phase. Incorporation of smallamounts of other monomers such as acrylonitrile or (meth)acrylonitrilewithin the resin shell also provides suitable impact modifiers. Theinterpenetrating network is provided when the monomers forming the resinphase are polymerized and cross-linked in the presence of the previouslypolymerized and cross-linked (meth)acrylate rubbery phase.

Preferred rubbers are graft or core shell structures with a rubberycomponent with a Tg below 0° C., preferably between about −40° to −80°C., composed of poly alkylacrylates or polyolefins grafted with PMMA orSAN. Preferably the rubber content is at least 40 wt %, most preferablybetween about 60–90 wt %.

Especially suitable rubbers are the butadiene core-shell polymers of thetype available from Rohm & Haas, for example Paraloid® EXL2600. Mostpreferably, the impact modifier will comprise a two stage polymer havingan butadiene based rubbery core and a second stage polymerized frommethylmethacrylate alone or in combination with styrene. Surprisingly,with opaque impact modifiers like MBS EXL2600, the effect of adding PCCDto these PC/impact modifier compositions had very similar results; hightransmissions and low haze values were obtained with modifiers, eachmodifier having a unique PC/PCCD ratio to match the RI of thermoplasticblend to the RI of the impact modifier.

Other suitable rubbers are the ABS types Blendex® 336 and 415, availableform GE Specialty Chemicals. Both rubbers are based on impact modifierresin of SBR rubber. Although the mentioned rubbers appear to be verysuitable, there are many more rubbers which can be used. Actually anyrubber which has a reasonable clarity and which has an RI between the RIof the components of the miscible resin blend can be used, for examplebetween 1.51 and 1.58 when the blend is PC and PCCD can be used to thepresent invention.

The ABS type thermoplastic resins utilized by the present invention aregraft copolymers of vinyl cyanide monomers, di-olefins, vinyl aromaticmonomers and vinyl carboxylic acid ester monomers. Thus applicantsdefine herein the phrase ABS type or acrylonitrile-butadiene-styrenetype to include the group of polymers derived from vinyl cyanidemonomers, di-olefins, vinyl aromatic monomers and vinyl carboxylic acidester monomers as hereinafter defined. Vinyl cyanide monomers are hereindefined by the following structural formula:

where R is selected from the group consisting of hydrogen, alkyl groupsof from 1 to 5 carbon atoms, bromine and chlorine. Examples of vinylcyanide monomers include acrylonitrile, methacrylonitrile,ethacrylonitrile, (-chloroacrylonitrile and (-bromoacrylonitrile. Thediolefins utilized in the present invention are herein defined by thefollowing structural formula:

where each Q is independently selected from the group consisting ofhydrogen, alkyl groups of from 1 to 5 carbon atoms, bromine andchlorine. Examples of di-olefins include butadiene, isoprene,1,3-heptadiene, methyl-1,3-pentadiene, 2,3-dimethylbutadiene,2-ethyl-1,3-pentadiene, 1,3-hexadiene, 2,4-hexadiene, chlorobutadiene,bromobutadiene, dichlorobutadiene, dibromobutadiene and mixturesthereof. Vinyl aromatic monomers are herein defined by the followingstructural formula:

where each X is independently selected from the group consisting ofhydrogen, alkyl groups of from 1 to 5 carbon atoms, cycloalkyl, aryl,alkaryl, aralkyl, alkoxy, aryloxy and halogen and where R isindependently selected from the group consisting of hydrogen, alkylgroups of from 1 to 5 carbon atoms, bromine and chlorine. The phraseindependently selected means that co-polymers, terpolymers, or otherinterpolymers of these vinyl cyanide monomers may have an independentlyselected R for the vinyl cyanide relative to the R selected for thevinyl aromatic monomer. Examples of substituted vinyl aromatic monomersinclude styrene, 4-methylstyrene, vinyl xylene, 3,5-diethylstyrene,p-tert-butyl-styrene, 4-n-propyl styrene, (-methyl-styrene,(-ethyl-styrene, (-methyl-p-methylstyrene, p-hydroxy-styrene,methoxy-styrenes, chloro-styrene, 2-methyl-4-chloro-styrene,bromo-styrene, (-chloro-styrene, (-bromo-styrene, dichloro-styrene,2,6-dichloro-4-methylstyrene, dibromo-styrene, tetrachloro-styrene andmixtures thereof. Vinyl carboxylic acid ester monomers (esters ofalpha-, beta-u unsaturated carboxylic acids) are herein defined by thefollowing structural formula:

where J is selected from the group consisting of hydrogen and alkylgroups of from 1 to 8 carbon atoms and A is selected from the groupconsisting of alkyl groups of from 1 to 5 carbon atoms. Examples ofvinyl carboxylic acid ester monomers include methyl methacrylate, methylacrylate, ethyl methacrylate, ethyl acrylate, butyl methacrylate, butylacrylate, propyl methacrylate, propyl acrylate, 2-ethylhexyl acrylate,2-ethylhexyl methacrylate, methyl ethacrylate and mixtures thereof.

It will be understood that by the use of “monomers” are included all ofthe polymerizable species of monomers and copolymers typically utilizedin polymerization reactions, including by way of example monomers,homopolymers of primarily a single monomer, copolymers of two or moremonomers, terpolymers of three monomers and physical mixtures thereof.For example, a mixture of polymethylmethacrylate (PMMA) homopolymer andstyrene-acrylonitrile (SAN) copolymer may be utilized to form the “freerigid phase”, or alternatively amethylmethacrylate-styrene-acrylonitrile (MMASAN) terpolymer may beutilized.

Various monomers may be further utilized in addition to or in place ofthose listed above to further modify various properties of thecompositions disclosed herein. In general, the components of the presentinvention may be compounded with a copolymerizable monomer or monomerswithin a range not damaging the objectives and advantages of thisinvention. For example, in addition to or in place of SBR, the rubberphase may be comprised of polybutadiene, butadiene-acrylonitrilecopolymers, polyisoprene, EPM and EPR rubbers (ethylene/propylenerubbers), EPDM rubbers (ethylene/propylene/non-conjugated diene rubbers)and crosslinked alkylacrylate rubbers based on C₁–C₈ alkylacrylates, inparticular ethyl, butyl and ethylhexylacrylates, either alone or as amixture of two or more kinds. Furthermore, the rubber may compriseeither a block or random copolymer. In addition to or in place ofstyrene and acrylonitrile monomer used in the graft or free rigid phase,monomers including vinyl carboxylic acids such as acrylic acid,methacrylic acid and itaconic acid, acrylamides such as acrylamide,methacrylamide and n-butyl acrylamide, alpha-, beta-unsaturateddicarboxylic anhydrides such as maleic anhydride and itaconic anhydride,imides of alpha-, beta-unsaturated dicarboxylic acids such as maleimide,N-methylmaleinide, N-ethylmaleimide, N-Aryl maleimide and the halosubstituted N-alkyl N-aryl maleimides, imidized polymethyl methacrylates(polyglutarimides), unsaturated ketones such as vinyl methyl ketone andmethyl isopropenyl ketone, alpha-olefins such as ethylene and propylene,vinyl esters such as vinyl acetate and vinyl stearate, vinyl andvinylidene halides such as the vinyl and vinylidene chlorides andbromides, vinyl-substituted condensed aromatic ring structures such asvinyl naphthalene and vinyl anthracene and pyridine monomers may beused, either alone or as a mixture of two or more kinds.

Preferred impact modifiers are of the type disclosed in U.S. Pat. No.4,292,233, incorporated by reference. These impact modifiers comprise,generally, a relatively high content of a cross-linked butadiene polymergrafted base having grafted thereon acrylonitrile and styrene.

The acrylonitrile-butadiene-styrene type (ABS) thermoplastic resin ispreferably based on a SBR high rubber graft with a SAN free rigid phase.Rubber amounts between about 20 percent and about 45 percent arepreferred. This ABS composition preferably comprises: a) a free rigidphase derived from a vinyl aromatic monomer and a vinyl carboxylic acidester monomer, wherein the free rigid phase is present at a weightpercent level of from about 30 to about 70 percent by weight based onthe total weight of the composition, more preferably from about 35 toabout 50 percent by weight thereof, and most preferably from about 38 toabout 47 percent by weight thereof; b) a graft copolymer (graft phase)comprising a substrate copolymer and a superstrate copolymer wherein thesubstrate copolymer comprises a copolymer derived from a vinyl aromaticmonomer and a di-olefin and wherein the superstrate copolymer comprisesa copolymer derived from an aromatic monomer wherein the graft copolymeris present at a level of from about 30 to about 70 weight percent of thetotal weight of the composition, more preferably from about 50 to about65 percent by weight thereof, and most preferably from about 53 to about62 percent by weight thereof; and c) wherein the refractive index of thefree rigid phase and the calculated refractive index of the graft phaseare approximately the same (that is, matched to within about 0.005 orless). The refractive index of the phases may be readily calculatedbased on the weight percentage of the components and their refractiveindices, for example:

The refractive indices of butadiene, styrene, acrylonitrile and methylmethacrylate homo-polymers are 1.515, 1.591, 1.515 and 1.491respectively. A butadiene/styrene ratio of 85:15 gives a calculatedrefractive index of (0.85×1.515)+(0.15×1.591)=˜1.526.

The grafted SAN having a styrene to acrylonitrile ratio of 80:20 gives acalculated refractive index of (0.80×1.591)+(0.20×1.515)=˜1.576.

A graft copolymer of 65% styrene-butadiene rubber (butadiene:styrene=85:15) and 35% grafted SAN (styrene: acrylonitrile=80:20) givesa calculated refractive index of (0.65×1.526)+(0.35×1.576)=˜1.544.

In the example above, the free rigid phase must have approximately thesame refractive index as the graft rubber phase within ±0.005. A freerigid phase of 60% PMMA and 40 percent SAN of 75% styrene and 25%acrylonitrile has a refractive index of approximately 1.539, therebymatching the graft phase refractive index to within 0.005.

The free rigid phase is preferably derived from styrene-acrylonitrile(SAN). The ratio of styrene to acrylonitrile is preferably from 1.5 to15 (that is, preferably from about 60 percent to about 94 percentstyrene) and from about 6 percent to about 40 percent acrylonitrile byweight based on the total weight of the free rigid phase, morepreferably from about 4 to 12 (from about 80 percent to about 92 percentstyrene) and from about 8 percent to about 20 percent acrylonitrile byweight based on the total weight of the free rigid phase and mostpreferably from about 6 to 9 (from about 85 percent to about 90 percentstyrene) and from about 10 percent to about 15 percent acrylonitrile byweight based on the total weight of the free rigid phase. The graftcopolymer is preferably derived from a vinyl aromatic-di-olefin rubbersubstrate copolymer. The graft copolymer preferably comprises from about40 percent to about 90 percent of a substrate copolymer and from about10 percent to about 60 percent of a superstrate copolymer based on thetotal weight of the graft copolymer, more preferably from about 55percent to about 75 percent of a substrate copolymer and from about 25percent to 45 percent of a superstrate copolymer by weight thereof, andmost preferably about 65 percent by weight of a substrate copolymer and35 percent by weight of a superstrate copolymer. The substrate copolymerpreferably comprises a vinyl aromatic component level of from slightlygreater than about 0 percent to about 30 percent by weight based on thetotal weight of the substrate copolymer, more preferably from 10 to 20percent by weight thereof and most preferably 15 percent by weightthereof, and a di-olefin component level of from about 70 percent toabout 100 percent of a di-olefin by weight based on the total weight ofthe substrate copolymer, more preferably from about 80 to about 90percent by weight thereof, and most preferably about 85 percent byweight thereof. The superstrate may optionally contain a vinylcarboxylic acid ester component such as methyl methacrylate. The graftphase preferably has a weight average particle size of less than 2400angstroms (0.24 microns), more preferably less than 1600 angstroms (0.16microns) and most preferably less than 1200 angstroms (0.12 microns).Generally, the particle size of the rubber has an effect upon theoptimum grafting level for the graft copolymer. As a given weightpercentage of smaller size rubber particles will provide greater surfacearea for grafting than the equivalent weight of a larger rubber particlesize, the density of grafting may be varied accordingly. In general,smaller rubber particles preferably utilize a highersuperstrate/substrate ratio than larger size particles to give generallycomparable results.

The graft phase may be coagulated, blended and colloided with the freerigid phase homopolymers, copolymers and/or terpolymers by the variousblending processes that are well known in the art to form the ASApolymer polyblend.

Preferred Compositions of the Invention

The preferred impact-modified, cycloaliphatic polymer compositions ofthe, present invention comprise:

(A) from 20 to 80% by weight of a blend of polycarbonate and cycloaliphatic polyester resin, where the ratio of polycarbonate to cycloaliphatic polyester resin is from 20/80 to 95/5, preferable from 30/70to 60/40, the cyclo aliphatic polyester comprises the reaction productof:

(a) at least one straight chain, branched, or cycloaliphatic C₂–C₁₂alkane diol, most preferably a C₆–C₁₂ cycloaliphatic diol, or chemicalequivalent thereof; and

(b) at least one cycloaliphatic diacid, most preferably a C₆–C₁₂ diacid,or chemical equivalent thereof; and

(B) from 1 to 30%, preferably from 5 to 20% by weight of an impactmodifier comprising a substantially amorphous resin comprising one ofseveral different modifiers or combinations of two or more of thesemodifiers. Suitable are the groups of modifiers known as ABS modifiersASA modifiers, MBS modifiers, EPDM graft SAN modifiers, acrylic rubbermodifiers.

The method of blending the compositions can be carried out byconventional techniques. Preferably the polyester and polycarbonate arepre-blended in an amount selected to match the refractive index of themodifier. The ingredients are typically in powder or granular form,extruding the blend and comminuting into pellets or other suitableshapes. The ingredients are combined in any usual manner, e.g., by drymixing or by mixing in the melted state in an extruder, or in othermixers.

Impact modified polycarbonate resins as outlined above are excellentmaterials for applications requiring high impact, chemical resistance,and appealing aesthetic. In order to improve the appearance, specialeffect additives have been utilized as colorants. U.S. Pat. No.5,510,398 to Clark et al relates to a highly filled, extrudedpolyalkylene terephthalate resin, a polycarbonate resin, a filler, astabilizer, and a non-dispersing pigment to give the extrudedthermoplastic material a speckled surface appearance. Column 5, lines 35to column 6, line 61, describes impact modifiers. U.S. Pat. No.5,441,997 to Walsh et al describes the use of impact modifiers inconjunction with polycarbonate/polyester compositions having a bariumsulfate, strontium sulfate, zirconium oxide, or zinc sulfate filler.U.S. Pat. No. 5,814,712 to Gallucci et al describes a glycidyl ester asan impact modifier, and optionally other impact modifiers, for apolycarbonate/polyester resin. U.S. Pat. No. 4,264,487 to Fromuth et aldescribes aromatic polycarbonate, acrylate-based core-shell polymer, andaromatic polyester.

Visual-Effect Additives

In the compositions of the invention, one or more visual-effectsadditives of various types may be added as desired.

Glitter Type of Materials

As the glitter material, it is suitable to use one or more kindsselected from the group consisting of mica, pearl mica, glass flake,aluminum powder, stainless powder, brass powder, metallic platingpowder, metallic coating powder, aluminum flake, aluminum foil, zinc,and bronze powder. This leads to an advantage of an excellent glitterfeeling. It is particularly preferable to use a glitter material havinga high transmittance with respect to a visible ray such as mica, pearlmica, glass flake, or the like. These materials further improve theglitter and color depth of a skin layer, and moreover, provide a colortone with high gloss, depth and glitter feel to the glitter resin moldedmaterial by light that has transmitted through the skin layer andreflected on the surface of a core layer which is colored with acoloring pigment.

The coloring pigment contained in the skin layer and the core layer issuitably one or more kinds selected from a group of organic pigmentssuch as phthalocyanine blue, cyanine green, indanthrene, azo,anthraquinone, perylene, perynone, quinacridone, isoindolinone,thioindigo, dioxazine; a group of inorganic pigments such as titaniumoxide, titanium yellow, red iron oxide, burned pigment, carbon black;and a group of dyes such as phthalocyanine, anthraquinone, perylene,perynone.

Granite Type of Additives

Many large opaque particles can be used to make the simulated granite.These particles can be colored or uncolored. Typical mineral particlesthat can be used are calcined talc, magnetite, siderite, ilmenite,goethite, galena, graphite, anthracite and bituminous coal,chalcopyrite, pyrite, hematite, limonite; pyroxenes such as augite;amphiboles such as hornblende; biotite, sphalerite, anatase, corunbum,diamond, carborundum, anhydrite, chalk, diurite, rutile, sandstone,shale, slate, sparite, vermiculite, natural granite, peat and basalt.Other useful materials are chips of brick, charcoal, concrete, plaster,porcelain, sawdust, seashells, slag, wood and the like, various filledor pigmented chips of insoluble or crosslinked polymers such as ABSresins, cellulose esters, cellulose ethers, epoxy resins, polyethylene,ethylene copolymers, melamine resins, phenolic resins, polyacetals,polyacrylics, polydienes, polyesters, polyisobutylenes, polypropylenes,polystyrenes, urea/formaldehyde resins, polyureas, polyurethanes,polyvinyl chloride, polyvinylidene chloride, polyvinyl esters and thelike.

Useful large translucent and transparent particles are natural orsynthetic minerals or materials such as agate, alabaster, albite,calcite, chalcedony, chert, feldspar, flint quartz, glass, malachite,marble, mica, obsidian, opal, quartz, quartzite, rock gypsum, sand,silica, travertine, wollastonite and the like; and moderately filled orunfilled, pigmented or dyed, insoluble or crosslinked chips of polymersreferred to in the last paragraph.

The large opaque, translucent and/or transparent particles are presentin the simulated granite at a concentration of about 0.1–50% by volume,preferably about 1–35% by volume. The opaque particles are mostpreferably at a concentration of about 5–25% by volume while theconcentration of the translucent or transparent particles is mostpreferably about 5–30% by volume.

Additional additives can be included in the simulated granite article togive it decorative effects or to color the matrix background. Theseadditives can be incorporated at a concentration up to about 10% byvolume; however, when dyes or pigments are used to color the matrix, thecolor concentration cannot be so great as to hide the large opaque,translucent and transparent particles. The optical density of a 0.05inch thick wafer must be less than 3.0 and the surface must exhibit agranite-like pattern.

The surface patterns of a number of different natural granites have beendefined by IMANCO® Quantimet 720 image analysis. These patterns haveabout 0.1 to 40% area detectable at densitometric level 820, about 0 to30% additional area detectable at level 860, about 0.1 to 25% additionalarea detectable at level 900, about 0 to 25% additional area detectableat level 950 and about 15 to 95% additional area detectable at a levelgreater than 950. It is preferred that the simulated granite haveessentially the same surface pattern.

In addition to dyes and pigments, other useful decorative additives aremetallic fibers, dusts, flakes, chips or shavings such as aluminum,copper, bronze, brass, chromium, nickel, gold, iron, steel, platinum,silver, tin, titanium, tungsten, zinc and the like; non-metallic chipsor flakes such as titanium nitride, nickel sulfide, cobalt sulfide,anhydrous chromic chloride and magnesium sulfide; and natural or coloredflocks or chopped fibers such as asbestos, rayon, cotton, nylon, flax,polyester, glass, hair, hemp, paper pulp, polyacrylonitrile,polyethylene, polypropylene, protein, rock wool, wood fiber, wool andthe like.

The simulated granite is prepared by first preparing a castablecomposition. This composition can be made by preparing a mixture of thelarge opaque particles, the large transparent and/or translucentparticles and, if desired, any of the solid optional ingredients such asthe decorative particles. The matrix for the composition is prepared bymixing the polymerizable constituent, a viscosity control constituent,an initiating amount of an initiator system for the polymerizableconstituent, the small filler particles and any other optionalingredients such as a cross-linking or coloring agent. These twomixtures are mixed at a ratio which will give the desired visual effectin the final product and then this final mixture, called the castablecomposition is poured onto a surface which takes the form of the finalarticle, e.g. a flat surface for simulated granite sheets or a mold forsimulated granite shaped articles. The poured mixture is then curedautogenically. The matrix mixing can be conducted at a temperature inthe range of about 20° to 50° C. provided that the initiator system isnot added until ready to cast.

Colored Pigments

In general, the effect pigment is a metallic-effect pigment, a metaloxide-coated metal pigment, a platelike graphite pigment, a platelikemolybdenumdisulfide pigment, a pearlescent mica pigment, a metaloxide-coated mica pigment, an organic effect pigment, a layered lightinterference pigment, a polymeric holographic pigment or a liquidcrystal interference pigment. Preferably, the effect pigment is a metaleffect pigment selected from the group consisting of aluminum, gold,brass and copper metal effect pigments; especially aluminum metal effectpigments. Alternatively, preferred effect pigments are pearlescent micapigments or a large particle size, preferably platelet type, organiceffect pigment selected from the group consisting of copperphthalocyanine blue, copper phthalocyanine green, carbazole dioxazine,diketopyrrolopyrrole, iminoisoindoline, iminoisoindolinone, azo andquinacridone effect pigments.

Suitable colored pigments especially include organic pigments selectedfrom the group consisting of azo, azomethine, methine, anthraquinone,phthalocyanine, perinone, perylene, diketopyrrolopyrrole, thioindigo,dioxazine iminoisoindoline, dioxazine, iminoisoindolinone, quinacridone,flavanthrone, indanthrone, anthrapyrimidine and quinophthalone pigments,or a mixture or solid solution thereof; especially a dioxazine,diketopyrrolopyrrole, quinacridone, phthalocyanine, indanthrone oriminoisoindolinone pigment, or a mixture or solid solution thereof.

Colored organic pigments of particular interest include C.I. Pigment Red202, C.I. Pigment Red 122, C.I. Pigment Red 179, C.I. Pigment Red 170,C.I. Pigment Red 144, C.I. Pigment Red 177, C.I. Pigment Red 254, C.I.Pigment Red 255, C.I. Pigment Red 264, C.I. Pigment Brown 23, C.I.Pigment Yellow 109, C.I. Pigment Yellow 110, C.I. Pigment Yellow 147,C.I. Pigment Orange 61, C.I. Pigment Orange 71, C.I. Pigment Orange 73,C.I. Pigment Orange 48, C.I. Pigment Orange 49, C.I. Pigment Blue 15,C.I. Pigment Blue 60, C.I. Pigment Violet 23, C.I. Pigment Violet 37,C.I. Pigment Violet 19, C.I. Pigment Green 7, C.I. Pigment Green 36, ora mixture or solid solution thereof.

Suitable colored pigments also include inorganic pigments; especiallythose selected from the group consisting of metal oxides, antimonyyellow, lead chromate, lead chromate sulfate, lead molybdate,ultramarine blue, cobalt blue, manganese blue, chrome oxide green,hydrated chrome oxide green, cobalt green and metal sulfides, such ascerium or cadmium sulfide, cadmium sulfoselenides, zinc ferrite, bismuthvanadate and mixed metal oxides.

Most preferably, the colored pigment is a transparent organic pigment.Pigment compositions wherein the colored pigment is a transparentorganic pigment having a particle size range of below 0.2 μm, preferablybelow 0.1 μm, are particularly interesting. For example, inventivepigment compositions containing, as transparent organic pigment, thetransparent quinacridones in their magenta and red colors, thetransparent yellow pigments, like the isoindolinones or the yellowquinacridone/quinacridonequinone solid solutions, transparent copperphthalocyanine blue and halogenated copper phthalocyanine green, or thehighly-saturated transparent diketopyrrolopyrrole or dioxazine pigmentsare particularly interesting.

Adding a fluorescent dyestuff generates striking visual effects for thearticle. Suitable fluorescent dyestuffs include Permanent Pink R (ColorIndex Pigment Red 181, from Clariant Corporation), Hostasol Red 5B(Color Index #73300, CAS # 522-75-8, from Clariant Corporation) andMacrolex Fluorescent Yellow 10GN (Color Index Solvent Yellow 160:1, fromBayer Corporation). Among these, Permanent Pink R is preferred.

Typically the pigment composition is prepared by blending the pigmentwith the filler by known dry or wet mixing techniques. For example, thecomponents are wet mixed in the end step of a pigment preparatoryprocess, or by blending the filler into an aqueous pigment slurry, theslurry mixture is then filtered, dried and micropulverized.

In a preferred method, the pigment is dry blended with the filler in anysuitable device which yields a nearly homogenous mixture of the pigmentand the filler. Such devices are, for example, containers like flasks ordrums which are submitted to rolling or shaking, or specific blendingequipment like for example the TURBULA mixer from W. Bachofen, CH-4002Basel, or the P-K TWIN-SHELL INTENSIFIER BLENDER from Patterson-KelleyDivision, East Stroudsburg, Pa. 18301.

The pigment compositions are generally used in the form of a powderwhich is incorporated into a high-molecular-weight organic composition,such as a coating composition, to be pigmented.

The pigment composition consists of or consists essentially of thefiller and colored pigment, as well as customary additives for pigmentcompositions. Such customary additives include texture-improving agentsand/or antiflocculating agents.

The following patents relate to metallic type pigments. WO 99/02594which describes the use of rectangular aluminum flakes in Nyloncompositions., U.S. Pat. No. 5,091,010 and EP 0 426 446 relate to theaesthetics of molded articles containing flakes. These references do notaddress mechanical performance concerns which are addressed by thepresent invention.

Among the problems to be solved when utilizing polycarbonate resins andparticles and pigments to produce special color effects are thoserelated to composition coloring and those related to producing a verybright, metallic reflective sparkle appearance in the molded articleswhile retaining impact strength and transparency. For most visualeffects, it is desirable to have a completely transparent matrix inorder to obtain the deepest color effect. The use of modifiers incombination various colorant additives may to be detrimental to physicalproperties such as notched Izod impact. Although various impactmodifiers are known in the prior art, the prior art is deficient inaddressing the problem of enhancing the impact properties ofpolycarbonate (alloys) having special effect colorants, whilemaintaining the transparency. The blend compositions as described inthis invention combine appealing aesthetics, chemical resistance, andhigh impact properties and will be useful in molded article applicationswhere this combination of properties is desirable.

Other Additives

Additionally, additives such as antioxidants, heat resisting agents,anti-weathering agents, mold release agents, lubricants, nucleatingagents, plasticizers, flow-improving agents and anti-statics, quenchers,minerals such as talc, clay, mica, barite, wollastonite and otherstabilizers including but not limited to UV stabilizers, such asbenzotriazole, supplemental reinforcing fillers such as flaked or milledglass, and the like, flame retardants, pigments or combinations thereofmay be added to the, compositions of the present invention. Theseadditives may be introduced in a mixing or molding process, provided theproperties of the composition are not damaged.

Suitable antistatic agents include, but are not limited to, phosphoniumsalts, polyalkylene glycols, sulfonium salts and alkyl and aryl ammoniumsalts.

Suitable mold release agents include, but are not limited to,pentaerythritol tetracarboxylate, glycerol monocarboxylates, glyceroltricarboxylates, polyolefins, alkyl waxes and amides.

In the thermoplastic compositions which contain a cycloaliphaticpolyester resin and a polycarbonate resin it is preferable to use astabilizer or quencher material. Catalyst quenchers are agents whichinhibit activity of any catalysts which may be present in the resins.Catalyst quenchers are described in detail in U.S. Pat. No. 5,441,997.It is desirable to select the correct quencher to avoid color formationand loss of clarity to the polyester polycarbonate blend.

A preferred class of stabilizers including quenchers are those whichprovide a transparent and colorless product. Typically, such stabilizersare used at a level of 0.001–10 weight percent and preferably at a leveloff from 0.005–2 weight percent. The favored stabilizers include aneffective amount of an acidic phosphate salt; an acid, alkyl aryl ormixed phosphite having at least one acidic hydrogen; a Group IB or GroupIIB metal phosphate salt; a phosphorus oxo acid, a metal acidpyrophosphate or a mixture thereof. The suitability of a particularcompound for use as a stabilizer and the determination of how much is tobe used as a stabilizer may be readily determined by preparing a mixtureof the polyester resin component and the polycarbonate and determiningthe effect on melt viscosity, gas generation or color stability or theformation of interpolymer. The acidic phosphate salts include sodiumdihydrogen phosphate, mono zinc phosphate, potassium hydrogen phosphate,calcium dihydrogen phosphate and the like. The phosphites may be of theformula V:

where R1, R2 and R3 are independently selected from the group consistingof hydrogen, alkyl and aryl with the proviso that at least one of R1, R2and R3 is hydrogen.

The phosphate salts of a Group IB or Group IIB metal include zincphosphate and the like. The phosphorus oxo acids include phosphorousacid, phosphoric acid, polyphosphoric acid or hypophosphorous acid.

The polyacid pyrophosphates may be of the formula VI:MzxHyPnO3n+1wherein M is a metal, x is a number ranging from 1 to 12 and y is anumber ranging 1 to 12, n is a number from 2 to 10, z is a number from 1to 5 and the sum of (xz)+y is equal to n+2. The preferred M is analkaline or alkaline earth metal.

The most preferred quenchers are oxo acids of phosphorus or acidicorgano phosphorus compounds. Inorganic acidic phosphorus compounds mayalso be used as quenchers, however they may result in haze or loss ofclarity. Most preferred quenchers are phosphoric acid, phosphorous acidor their partial esters.

The glass transition temperature of the preferred blend will be from 60to 150° C. with the range of 90–150° C. most preferred.

A flexural modulus (as measured by ASTM method D790) at room temperatureof greater than or equal to 150,00 psi is preferred, with a flexuralmodulus of greater than or equal to 250,000 psi being more preferred.

The yellowness index (YI) will be less than 10, preferably less than 5as measured by ASTM method D1925.

Haze, as measured by ASTM method D1003, will be below 5% in thepreferred composition, however in some cases higher haze levels (5–60%)are preferred in cases where the highest heat resistance is needed.

Above described materials have also been tested in GE StructuredProducts applications like film and coextruded solid sheet materials. Infilm advantages like “cold” forming (the low Tg of the material enablesthe operator to use lower temperatures to thermoform the film), improvedtensile impact and chemical resistance were seen. These products willperfectly suit in applications like eg. transparent keypads for mobilephones, where customers require the possibility to form these films atlow temperatures (below 100° C.) and further require an improved punchductility and chemical resistance. Other typical applications of suchfilms are automotive trim, automotive interior parts, portabletelecommunications and appliance fronts. Another advantage in filmapplications is the possibility to add Visual effects pigments (such ascoated Al and glass flakes), which are normally negatively affecting themechanical properties of Polycarbonate, to this PC/PCCD/ABS blend toenhance required Impact properties. These films can be used in directfilm applications but also in processes like IMD (In Mould Decoration).

EXAMPLES

The following examples serve to illustrate the invention but are notintended to limit the scope of the invention. Blends were prepared bytumbling all ingredients together for 1–5 min at room temperaturefollowed by extrusion at 250–300° C. on a co-rotating 30 mm vacuumvented twin screw extruder. Blends were run at 300 rpm. The output wascooled as a strand in a water bath and pelletized.

The resultant materials were dried at 100–120° C. for 3–6 h andinjection molded in discs or sections of discs (fans) for evaluation ofoptical properties.

Blends of PCCD with BPA-PC and various impact modifiers were preparedand various stabilizers were added to give good color and meltstability. The samples were compounded on a twin screw extruder andinjection-molded at standard conditions.

Example 1

MVR PC PCCD (cc/10′) 105 4000 Impact PC/PCCD Transmission (300° C. D/BBatch # grade % poise % stabilizers % Modifier % ratio 2 mm % 1.2 kg) °C. 1 99.8 0.2 91.4 5.1 −10 2 69.6 30 0.4 70/30 90.4 16.8 0 3 28.4 66.20.4  5% MBS 30/70 89.5 31.6 −20 4 25.4 59.2 0.4 15% MBS 30/70 88.5 14.3−32 5 30.6 54 0.4 15% clear 36/64 89.6 22.2 −6 ABS 6 47.3 47.3 0.4 10%ABS 415 50/50 89.8 7.4 −22 7 46.6 38.1 0.4 15% ABS 336 45/50 88.1 6.7−33 8 67.2 22.4 0.4 10% ABS 336 25/75 77.1 4.8 −32

From the data batch 1–7 it is clear that adding PCCD to PC gives asignificant improvement in flow. Adding impact modifiers not only givesan improvement in flow, but also improves low temperature ductility,while obtaining high transparencies in the same range as PC.

In some cases lower amounts of PCCD are desired, than the ones mentionedin batch 2–7. This can be from a cost perspective or that for someapplications more heat is required. Although this will result in lowertransmission values (the 100% match of RI is no longer present in theblend), in many cases these values are still high enough to allow foradding special/visual effects like glass or metal flakes and in somecases some translucency is even desired. A typical example is given inthe table for batch 8.

Example 2

These property enhancements are further illustrated in the next table,in which some typical comparisons are made between PC formulated withspecial effects and blends of PC/PCCD and impact modifier, formulatedwith the same type of special effects.

MVR PC PCCD (cc/10′) 105 2000 Impact (265° C. D/B batch # grade % poise% stabilizers % Modifier % Special Effect 5 kg) ° C. 9 98.3 0.5 1.2%glass/silver 10.1 >25 flakes 10 41.7 41.7 0.4 15% ABS 1.2% glass/silver12.8 −22 415 flakes 11 99.3 0.5 0.2% variochr. red 10.4 >25(AngularMetameric) 12 41.7 41.7 0.4 15% ABS 0.2% variochr. red 12.8 −18415 (AngularMetameric)

It is obvious from the data that typical effects like glass and metalflakes turn PC into very brittle blends. However with the correct PCCDand impact modifier loading, the visual effect was very similar to thePC sample, but the blend was still ductile at lower than 0° C. and evenhad an improved flow. This remarkable achievement of highly ductile,transparent materials with special effects like Angular Metamerism,Diamond, Diffusion and Pearl effects is not restricted to the onesmentioned in the examples.

Example 3

Film material with a thickness of 220 microns was produced from a45/45/10% ratio PC/PCCD/ABS blend and tested with 100% PC film as areference material. Following results were obtained:

Film sample 2 Film sample 3 Film sample 1 45/45/10% 40/60% Test name:100% PC PC/PCCD/ABS PC/PCCD Tensile Impact Kj/m2 961 1129 1147Elongation to br. % 75.2 98.3 87.5 After stress cracking 102.8 126.4154.6 “sweat” test: Tensile Strain at max % Taber Abrasion ASTM 27 24 19D1044 25 Rotations Haze %

From this example it is apparent that impact properties of film materialmade from PC/PCCD mixtures is improved significantly compared to PCalone, either with or without adding impact modifiers. Also the chemicalresistance towards artificial sweat has improved.

Example 4

The polyester PCCD (with low RI[RI of PCCD˜1.525) that is fully misciblewith PC can be used to lower the RI of the PC phase (phase 1) to the RIof a clear ABS (that has RI of SAN and Rubber phases already matched).This results in transparent PC/SAN/rubber blend. Mixtures of PC/PCCDresulted in linear RI going from 1.525 to 1.577 when using 100% PCCD to100% PC respectively. The Clear ABS that was utilized in this examplehad a RI of 1.548. In order to match this a PC/PCCD ratio of 54 to 31was prepared and mixed with 15 wt. % of clear ABS. The results ofsamples from this blend were as follows:

Transmission (%, 3.2 mm) 85 Haze (ASTM9125) 15

The refractive index of pure polycarbonate (PC) is 1.586 while that ofPCCD is 1.516. In a mixture of polycarbonate and poly(1,4-cyclohexanedimethanol-1,4-cyclohexanedicarboxylate the refractiveindex of the mixture, y, varies as the function −0.0007 (weight percentpoly (1,4-cyclohexanedimethanol-1,4-cyclohexanedicarboxylate)+1.586 witha regression R squared coefficient of 0.998. Thus the refractive indexof the mixture of the two components may be controlled between the upperand lower limits of their respective indices of refraction.

1. A composition comprising a uniform blend of: a) a resin blend of apolycarbonate resin and a cycloaliphatic polyester resin, saidcycloaliphatic polyester resin comprising the reaction product of analiphatic C2–C12 diol or chemical equivalent and a C6–C12 aliphaticdiacid or chemical equivalent, said cycloaliphatic polyester resincontaining at least about 80% by weight of a cycloaliphatic dicarboxylicacid, or chemical equivalent, and/or of a cycloaliphatic dial orchemical equivalent; and b) an impact modifying amorphous resin having arefractive index from about 1.51 to about 1.58, wherein the impactmodifying amorphous resin comprises a MBS core-shell polymer and an ABSrubber; wherein the miscible blend comprises the polycarbonate and thecycloaliphatic polyester resin in amounts such that the index ofrefraction of the blend matches the index of refraction of said impactmodifier to produce a transparent or translucent composition.
 2. Thecomposition according to claim 1, wherein the cycloaliphatic polyesterresin comprises the reaction product of a C6–C12 cycloaliphatic dial orchemical equivalent and a C6–C12 cycloaliphatic diacid or chemicalequivalent.
 3. The composition according to claim 2, wherein the ratioof polycarbonate resin to cycloaliphatic polyester resin in the blend isfrom 95/5 to 20/80, and wherein the composition comprises from 1 to 30%by weight of the impact modifying amorphous resin.
 4. The compositionaccording to claim 1 where the blend has % transmittance of greater thanor equal to 75%.
 5. The composition according to claim 1 where the blendhas a glass transition temperature of from 60 to 150° C.
 6. Thecomposition according to claim 1 with the addition of about 0.0001 toabout 7 percent by weight of metal or mineral flakes for imparting adesired visual effect, said impact modifier enhancing the impactstrength of molded composition as compared to a molding compositionabsent said impact modifier.
 7. The composition according to claim 6wherein said flakes are aluminum.
 8. The composition according to claim6 wherein the flakes comprise from about 0.05 to about 5.0 weightpercent of the resin composition.
 9. The composition according to claim6 wherein said flakes are metal and range in size from 17.5 microns to650 microns.
 10. The composition according to claim 6 wherein the flakesare metal and are selected from the group consisting of metals of GroupI-B, III-A, IV, VI-B and VIII of the periodic table and physicalmixtures and alloys of these metals.
 11. The composition according toclaim 6 wherein the flakes are mica.
 12. The composition according toclaim 6 wherein the flakes are metal and selected from the groupconsisting of aluminum, bronze, brass, chromium, copper, gold, iron,molybdenum, nickel, tin, titanium and zinc, alloys of these metals andphysical mixtures thereof.
 13. The composition according to claim 6further comprising a background colorant having a different colorationthan said flakes.
 14. The composition according to claim 13 wherein saidcolorant is selected from the group consisting of carbon black,phthalocyanine blues, phthalocyanine greens, anthraquinone dyes, scarlet3b Lake, azo compounds, acid azo pigments, quinacridones,chromophthalocyanine pyrrols, halogenated phthalocyanines, quinolines,heterocyclic dyes, perinone dyes, anthracenedione dyes, thioxanthenedyes, parazolone dyes and polymethine pigments.
 15. The compositionaccording to claim 1 where the blend further contains an effectiveamount of a stabilizer to prevent color formation.
 16. The compositionaccording to claim 15 wherein the stabilizer is chosen from the groupconsisting of: phosphorus oxo acids, acid organo phosphates, acid organophosphites, acid phosphate metal salts, acidic phosphite metal salts ormixture thereof giving an article with greater than or equal to about70% transmittance.
 17. The composition according to claim 1 wherein thecycloaliphatic polyester is comprised of cycloaliphatic diacid andcycloaliphatic diol units.
 18. The composition according to claim 17where the polyester is polycyclohexane dimethanol cyclohexanedicarboxylate (PCCD).
 19. The composition according to claim 17 wherethe polycarbonate is BPA-PC and the cycloaliphatic polyester is PCCD.20. The composition according to claim 1 where the ratio ofcycloaliphatic polyester to polycarbonate in the blend is 5/95 to 80/20.21. The composition according to claim 20 wherein said blend furthercontains an effective amount of a stabilizer to prevent color formation.22. The composition according to claim 21 wherein said stabilizer ischosen from the group consisting of: phosphorus oxo acids, acid organophosphates, acid organo phosphites, acid phosphate metal salts, acidicphosphite metal salts or mixture thereof for making a molded articlewith greater than or equal to about 75% transmittance.
 23. Thecomposition according to claim 22 wherein said cycloaliphatic polyestercomprises cycloaliphatic diacid and cycloaliphatic diol units.
 24. Thecomposition according to claim 1, further comprising an effect-producingamount of an effect pigment, an effective coloring amount of a coloredpigment, and an effect-enhancing amount of a small particle size fillerhaving a porous surface.
 25. The composition according to claim 1,further comprising an effect-producing amount of a metallic, pearlescentmica or graphite effect pigment, a transparent organic pigment as thecolored pigment and an effect-enhancing amount of a small particle sizefiller having a porous surface.
 26. A process for molding a transparentarticle comprising the steps of (a) selecting a transparent impactmodifier having a predetermined index of refraction, wherein the impactmodifying amorphous resin comprises a MBS core-shell polymer and an ABSrubber, (b) forming a resin blend comprising a cycloaliphatic polyesterand a polycarbonate, wherein the cycloaliphatic polyester and thepolycarbonate are mixed in the resin blend in proportions such that theresin blend has an index of refraction that substantially matches thepredetermined index of refraction, (c) forming a molding compositioncomprising the selected impact modifier and the resin blend; and (d)molding an article from the molding composition.
 27. The process ofclaim 26, wherein said molding is carried out above the glass transitiontemperature of said resin blend, said resin blend having a glasstransition temperature of from about 60 to 150° C.
 28. The process ofclaim 27 wherein said molding is carried out by injection molding.
 29. Aprocess for forming a molding composition for preparing transparentarticles comprising the steps of (a) selecting a transparent impactmodifier having a predetermined index of refraction, wherein the impactmodifying amorphous resin comprises a MBS core-shell polymer and an ABSrubber, (b) forming a resin blend comprising a cycloaliphatic polyesterand a polycarbonate in proportions such that the resin blend has anindex of refraction that substantially matches the predetermined indexof refraction, and (c) mixing the impact modifier and the resin blend toform a molding composition.
 30. A transparent extrusion sheet producthaving a thickness of from 10 um to 12 mm formed from a compositionaccording claim 1.